1)

REPUGNANT : REPEL::


A) illogical: upset

B) cogent:convince

C) risky : avoid

D) fluent: refine

Answer:

Option B

Explanation:

(SYNONYM VARIANT) We are repelled (meaning disgusted) by a repugnant (meaning extremely undesirable) action; we are convinced by a cogent (meaning logical) argument. (B){The related synonym relationship is repugnant : repelling :: cogent : convincing}